Ford 1700 Hydraulic Pump

[hgd1956]

I have a 1979 Ford 1700. I bought it as a basket case and it have proven to be a real challenge getting in running shape. I managed to get it all together only to find that the hydraulic pump is very weak. No real pressure and the flow is low as well. When I bought the tractor it had been sitting for about 6 years apparrently outside. I have pulled the pump and disassembled it only to find that it has been damaged internally and needs to be replaced or repaired. This is the problem, New Holland has a new pump, 845 dollars or a rebuild kit that only addresses the seals and such, no internal parts. Also, it appears that the early 1700s had a bigger pump than the later models. I ordered a used pump from LCI and of course it was the smaller later model. Help Please...........................this thing is killing me!

 

[JC-jetro]

I have a 1979 Ford 1700. I bought it as a basket case and it have proven to be a real challenge getting in running shape. I managed to get it all together only to find that the hydraulic pump is very weak. No real pressure and the flow is low as well. When I bought the tractor it had been sitting for about 6 years apparrently outside. I have pulled the pump and disassembled it only to find that it has been damaged internally and needs to be replaced or repaired. This is the problem, New Holland has a new pump, 845 dollars or a rebuild kit that only addresses the seals and such, no internal parts. Also, it appears that the early 1700s had a bigger pump than the later models. I ordered a used pump from LCI and of course it was the smaller later model. Help Please...........................this thing is killing me!

Been there, done that !!! I would not lose hope just yet. Please read the link below. It might be more read that you might like but passed the list seal the rest is pump stuff. Take pictures of the gears, and inside of the pump case and report back. There might be some tell tale sign that we might find. A repair seal kit along with a separate shaft seal might do the trick in lieu of $850 pump. You might have dirty screen leading to low gpm. How did you figure out your gpm? report back with your finding and we'll help.

JC,


http://www.tractorbynet.com/forums/new-holland-owning-operating/90819-my-f-1700-testing-my.html

 

[hgd1956]

Since my last posting I have learned a few things. First, the damage inside the pump was very minor. I buffed the aluminum pieces to remove the light marks and reinstalled the gears. After reading you entire posting, I realized that my seals were toast and they were probably the culprit. I ordered the seal yesterday and will get them in a couple of days. Back to your other questions, when I got the tractor it was full of water in the transmision. I dropped all of the transmission/water fluid flushed then replace with fresh. Of course, I had a brain fart and did not check the suction screen, so I dropped it again and pulled the screen. It was clean as a whistle. More new fluid and still no 3 point hitch.................I then dropped the discharge line from the pump and started the tractor which assured me that the pump was primed. By timing the flow into my bucket It was easy to determine that my pump was not performing well at all. The flow was around a gallon per minute. That is when I pulled the pump and arrived at this point. HD

 

[JC-jetro]

So far so good... Not bad aye. make sure to change pump input shaft seal as well. It is about $10 if I remember it right. That might allow air to be sucked in causing priming loss. On mine actually the shaft seal was the culprit. As long as the pump is not running dry there still be hope. make sure to orient the seal inside right as they will cause a bypass flow to keep the bushing and shaft lubricated. One way that you can check the flow in a cleaner manner and also checking your spool valve flow is directed to hose attached where I have a P. gauge in the pic below on lift piston cylinder head. Use a bucket to capture the fluid. Lift arm up and flow, lift arm down all the way no flow. I'm optimistic you'll fix it. Report back with your progress.

JC,


Edit;Once you get the pump working like it should and no 3 points, then you still might need to change the lift seal. even at reduced pump flow it the lift should still work but slow and not robust. Seal change was also on my posting and is a simple task. Spool valve operation is important as you can easily check it like how I suggested above.

 

[old1500]

I have a 1500, but I think we are like....sisters or something. So many components will interchange with the 1700. We have to be close-kin.

I have a "jerky" 3PH. It works, but a bit jerky on the up-swing with a load on it. I have it down working on something else, but went ahead and replaced my hydro-fluid. Mine has a strainer-cup right on top of the pump and when I pulled it....it looked like a family of mice had been living in there. I cleaned the filter (mesh) screen real well and noticed there was no o-ring at the base of the cup. I says....surely you must have dropped it, but nope...no o-ring to be found anywhere. I do not think it had been leaking as I have never noticed a greasy-spot on the shop floor. I don't know if any air could have been getting into the system from this connection, but I would suppose it would have been a leak under high pressure and no air could get in. My cylinder has had the seal replaced by the previous owner, at least the invoice he gave me when I bought the tractor it said the dealer did anyway.

I am hoping for smoother performance after a fluid change and filter clean...we'll see. Yes...I did put an o-ring back on the cover.

 

[hgd1956]

OK...........the hydraulic pump is rebuilt with new orings and seals installed and no improvement occurred. I can rule out my pump as the problem because it is in as good of shape as yours JC. I don't have a gauge to check the pressure but I feel sure it is low. My repair manual points to the unload valve assembly as the possible culprit. I can not find the little bugger! Is it inside the case behind the relief valve assembly? The book indicates that if that unload valve sticks open, then all of the fluid will just return to the crankcase and nothing goes to the lift cylinder. How do I get to it?

 

[JC-jetro]

OK...........the hydraulic pump is rebuilt with new orings and seals installed and no improvement occurred. I can rule out my pump as the problem because it is in as good of shape as yours JC. I don't have a gauge to check the pressure but I feel sure it is low. My repair manual points to the unload valve assembly as the possible culprit. I can not find the little bugger! Is it inside the case behind the relief valve assembly? The book indicates that if that unload valve sticks open, then all of the fluid will just return to the crankcase and nothing goes to the lift cylinder. How do I get to it?

A northern liq filled gauge from Northen is under $20 and it works fine for the price. Pic below shows the inside of the lift cover where you see the back of the spool valve. Look at the feed back arm that is externally attached to lift arm. That feed back arm returns the valve to neutral position at any given lift height, basically returns the fluid back to the rear diffy immediately below.



The feed back link on the outside. it goes thru the lift cover and ties in to the spool.



I would not just take the spool off and start tearing in to it as the replacement guts of it might be difficult to come by. Do all non destructive facts finding before tearing in to the spool, innards might be very expensive.

Do yourself a favor and invest in a gauge, one time use will pay for it self.

You might have a relief mechanism for your 3 point sets to a very low pressure causing most of the oil going in to the diffy rather than lift.





Did you do the flow test from my previous post?

JC,

 

[hgd1956]

Not yet.....I will go try to find a fitting and short hose to check the flow into a bucket. I am going to go over to Northern Tool and pick up a gauge as well. Keep you posted

 

[JC-jetro]

Not yet.....I will go try to find a fitting and short hose to check the flow into a bucket. I am going to go over to Northern Tool and pick up a gauge as well. Keep you posted

This is what I bought. Seems to be built well for the price.

JC,

Valley Instrument Grade A Stem Mount 2 1/2in. Glycerin Filled Gauge — 0-5000 PSI | Filled Gauges | Northern Tool + Equipment

 

[hgd1956]

Fixing to check flow. I did pull the plug, started the tractor and at idle no fluid came out. Held my finger over the hole and sped it up, it took a few seconds before the fluid arrived but I was able to keep the fluid at bay with my finger. I will go into Houston tomorrow and get the gauge but I really don't think it will much pressure. Of course when the pressure did start building, I pulled back on the throttle. Keep you posted